Wood is used in many applications that expose the wood to decay, fungi, or insects. To protect the wood, one alternative is to use traditional wood impregnation approaches, such as pressure treatment chemicals and processes. An alternative approach is to chemically modify the wood by reacting the wood with acetic anhydride and/or acetic acid. This type of modification is referred to as acetylation. Acetylation makes wood more resistant to decay, fungi, and insects.
Acetylation may be performed by first evacuating and then soaking the wood product in acetic anhydride, then heating it with optional pressure to cause a chemical reaction. Ideally, acetylation of wood products, such as planks, studs, and deck materials, would allow for large amounts of wood to be rapidly impregnated with the acetic anhydride. As such, any heating of wood products during acetylation would also ideally accommodate large quantities of wood products (e.g., bundles of boards). It would also be desirable to heat the wood products during acetylation evenly throughout the wood—thereby providing uniform modification of the wood and minimizing any damage to the wood caused by overheating due to hot spot formation. Thus, there is a need for improved mechanisms for heating wood products to facilitate acetylation.